According to the publication DE 10 2007 050 176 A1 the increasing complexity of cable looms, a strengthening of products liability regulations and increased requirements for warranties require a quality management with a monitoring of a crimping force when producing a crimped connection. It is proposed to equip crimping pliers with a force measuring device which is built by a piezo-electric force sensor or strain gauges. The force measuring device is located at the outside of a crimping plug or also within a crimping plug or in a crimping housing. The crimping pliers are further equipped with a transmitter which is located above the crimping plug at the crimping pliers head. The transmitter transmits a wireless crimping force signal which is received by an external receiving and evaluating device and which is then evaluated.
By operating elements it is possible to switch the transmitter on and off. Furthermore, by the operating elements it is possible to define the frequency of the transmitter. An energy source for the energy supply to the transmitter and the force measuring device which is built by an electrical battery or a reloadable accumulator is integrated into the transmitter. Furthermore, it is possible that the transmitter comprises an induction coil in which an outer magnet field is able to produce an inductive current for reloading the accumulator. It is also possible that the crimping pliers are equipped with a solar cell by which an alternative way for reloading the accumulator is provided. However, also a power supply to the force measuring device and the transmitter by a temporary cable connection is possible. The crimping pliers have a displaying device. The displaying device displays a crimping force, a transmitting frequency, an indication that there is a wireless connection, a loading state of the accumulator and the like. Here, the displaying device might be built as a LED- or LCD-device. Additionally, a displacement measuring system might be provided at the crimping pliers for sensing the working stroke of the crimping pliers. For avoiding damages it is possible that the crimping pliers comprise a latching device or a slipping clutch which limits the applicable crimping force to a predefined value. The receiving and evaluating device might e.g. be built by a customary personal computer with a bluetooth-receiver. Also a database might be used, wherein received signals are stored in order to reliably and permanently document the quality of the produced crimped connections.
The publication DE 298 06 179 U1 describes also measures for the documentation of the progression of a crimping force dependent on the crimping displacement. Here, both the crimping force as well as the crimping displacement are measured in the region of the bit of the pliers or in an intermediate part of a lever drive of the crimping pliers. An evaluating circuit can be provided at the crimping pliers with a suitable display for displaying information concerning the quality of the crimping process. It is possible that the crimping pliers comprise a data storage, wherein for different types of produced crimped connections (in particular different types of contact elements) force-displacement-progressions are stored. As an optical displaying device, a display basing on light-emitting diodes or a display basing upon liquid crystals might be used. Additionally, it is possible to output a signal via an acoustic displaying device. By different colors or tones of the displaying device it is possible to transmit different information concerning the quality of the produced crimping connection and of the crimping force-crimping displacement-progression. An optical interface or a cable-based interface or any possible interface transmitting via the air (which uses electromagnetic radiation in the visible, infrared or radiofrequency region) is used as an interface for a stationary processor, wherein it is also possible to use a bi-directional interface. An evaluation of the crimping force progression might be done by a comparison with a predetermined crimping force progression, in some cases under consideration of a given tolerance region. Furthermore, it is proposed to sense both the crimping force as well as the crimping displacement each by a force sensor. Here the crimping displacement is transformed by a spring which is biased over the crimping displacement into a force which is then sensed by the force sensor.
The publication DE 10 2004 009 489 B4 discloses the support of the setting process for the working stroke specific to the crimped workpiece by a sensoric registration and electronic processing of the position of the crimping plugs.
The publication DE 2 316 769 A describes a crimping machine not being of the generic type. In the crimping machine it is possible to read the number of executed working strokes from a counting mechanism. In the publication it is not further explained how the number of working strokes is sensed and for what purpose the counting mechanism displays the number of working strokes.
DE 297 03 052 U1 describes in a corresponding way a count storage for storing the number of executed crimping processes for a crimping machine not being of the generic type and having an electrical drive. A display of the number of the executed crimping processes is intended to alert the operator if a maintenance interval has been passed. When having executed the maintenance, the counter should again be reset with a subsequent restart of the counting procedure from the beginning.
The publication DE 10 2011 050 718 A1 proposes a method for monitoring the wear of pressing pliers or crimping pliers. The method is intended for detecting the different crimping forces and the different wear caused by the different forces during the crimping process of on the one hand smaller workpieces and on the other hand larger workpieces. For this purpose, the crimping pliers comprise an adjusting device for adjusting the distance between the crimping elements achieved with the complete closure of the crimping pliers. The adjusted distance is transferred to a microcontroller system of the crimping pliers. Furthermore, the signal of an end position switch located at abutting surfaces of the hand levers is transferred to the microcontroller system. The end position switch triggers a counting impulse if the hand levers are completely closed. A value for predicting the wear which is stored in a storage unit predicts a wear caused by one completely passed actuating stroke dependent on the distance defined by the adjusting device. Here, it is possible that the value for predicting the wear has been determined empirically or by tests, relies on experience or is stored as mathematical functions. The values for predicting wear are summed up with the passing of a plurality of closing strokes of the crimping pliers. If the sum of the values for predicting wear reaches a defined limit value, a demand for a calibration of the crimping pliers is provided at an output. This might be provided by a display present at the crimping pliers, an acoustic signal or a mechanical blocking device. The limit value might be defined by a standard to be met or might be defined by the manufacturer. It is possible that by means of the calibration the actual wear is determined which is then stored in the storage unit of the crimping pliers and which can be shown at the display which might also be connected with a display of a remaining usability in %. Subsequently, there might be a reset of the summed value of overall wear. Then the values for predicting wear are again summed up until another limit value is reached with a new demand for a calibration. If the overall lifetime has been reached, a warning might be displayed at the display or the crimping pliers are mechanically locked. Furthermore, it is possible that a sensor for sensing the crimping force is provided in order to suppress an empty actuation of the crimping pliers for which there is no wear of the crimping pliers.
The publication US 2010/0293720 A1 discloses crimping pliers, wherein a counting device is integrated into the end region of a hand lever facing away from the pliers head with an integration into a U-shaped recess of the hand lever. The counting device comprises a housing, a cover, a LCD-display, a reed-sensor and a controller. On a side facing away from the aforementioned hand lever, another hand lever carries a permanent magnet. The approaching of the permanent magnet at the reed-sensor when running through the closing stroke of the hand levers triggers a counting impulse.
The publication DE 1 490 170 A1 relates to a so called manual bead device (DE: “Handsickengerat”) which does not build hand pliers but has a pistol-like design with a handle and an actuating lever being mounted for being pivoted to the handle and building the trigger of the pistol-like design. The actuation lever acts via a redirecting lever, an actuating stamp, a latching toothing and a cam drive upon an actuating lever for producing the bead, wherein the actuating lever is biased by a spring package. The counting of the number of the completed closing strokes is here done by use of a mechanical counting device.
The publication U.S. Pat. No. 3,590,484 A discloses punching pliers for deactivating tickets, wherein the punching pliers comprise a mechanical counting device.
The publication U.S. Pat. No. 2,006,396 A also discloses punching pliers for deactivating tickets comprising a mechanical counting device.